Start 'em Young!
Fatherly (a blog that spans the adventure of fatherdom / parentdom, and thankfully includes real adventuring too!) recently posted a great piece on gear must-have's for getting out safely with little ones. I would add two more: gummy bears and training with an AMGA certified guide if needed. The gummy bears are the essential must-have...pre-climb the route placing the bears on key holds and bam!: no whining, just focused sending!